Methine dyestuffs



United. States Patent l Nicholas J. Kartinos; Niles, 'Ill., .assignor to General Aniline & Film Corporation,=-New:,York,"N. Y., a corporafion fiDel w r No Drawing. Application, Mar,ch 23, 1956, I -SerialNo. 573,327

This invention relates to-a new .class of dyestuffs which dye synthetic -,;fibers,- andzin particular cellulose carboxylic acid ester fibers with outstanding washand light-fastness, and inadditi-on, said dyestutfsv are possessed of unusual and unexpected tinctor-ial-ustrengthas compared to other si milarmeth-ine dyes.

I have discoveredthat the methine, dyes obtained by condensing cyanoethyl cyanoacetate ,with a 1 particular class of N-substituted p-aminobenzaldehydes in the presenceof a .basiccatalyst are outstanding inso far as itheirv lightand wash fastness are concerned and, further, vexl libit superior.properties with respect' to decreased sublimation and increased tinctorial-streng'th. The dyestuffs of .this invention ,yield iin general exceptionally bright, yellow or greenish-yellow dyeings on synthetic fibers and especially on cellulose vacetates.

The methine dyes of this inventionare-characterized by the following general tormula:

R2v represents a lower alkyl radical, for example, methyl, ethyl, n-propyl, isopropyL'n-butyl, isobutyl and the like;

R3 may be hydrogen, lower alkyl such as methyl, ethyl and the like, or a'cyloxymethyl; and X may be hydrogen or lower alkyl such as methyl, ethyl and the-like.

The: intermediatecyanoethyl"-cyanoacetate' may be prepared in accordance with a method described in copending application Serial No. 556,3 83-filed December 30, 1955. The following will serve to illustrate one of the methods described in the aforementioned application.

Ewmzz A Into a 2-liter flask arecharged:

340 g. cyanoacetic acid (4'moles) 355 g. ethylene cyanohydrin (Smoles) 600 g. chloroform- I 20 g. methane sulfonic acid 1 g The contents are thenheated under reflux-with a water separator until'no more water separates. The reaction mixture is cooled to about C. and then.

remains in the chloroform solution. This solution'is'then then removed by distillation. The residue is then disextracted 1 with a dilute solution ofsodiurn hydroxide" until no acid" dried over sodium sulfateffilteried and the-ch l-o1' ofo1'm "ice tilled-underredticed pressure. The resultant colorless cyanoethyl cyanoacetate has a boiling point of 182-490" C. at-1.'7 mm.

The V N-substituted p-arninobenzaldehyde derivatives suitable 'for use-in the preparationof the methineldyes of this inventioninclude the following:

{ ,13 (4-.formylphenyl ),-imino-bisethyl acetate ,B,'B"-( 4-formyl phenyl) -imino,- bis-ethyl propionate (ornomo momcmom-Q-ono [3,13 (3 methyl 4 formylphenyl) imino bis ethyl I propionate onto-mo OgOH CEQaN QCHO N ethyl-p-( leformylphenyl)-amino ethyl acetate N-ethyl-fl (4-formylphenyl)eaminoethylpropionate onzomooaorn'onr N ethyl p 3 methyl fl fortnylphenyl) aminoethyl propionate 011301110 memoir, V

\NV 0Ho CHaCg (N methyl) -N-(4-.formylphenyl) -aminoisopropyl acetate 3 (N methyl)-N(4 formylphenyl) -aminopropa'nedio dia'cetate-1,2

Y on; H 1 g I omom-ort-ofil lit-020011,

2 N (B chloroethyl) N (4 vformylphenyl) -aminoethyl acetate OICHZOHI B N (18' methoxyethyl) r N (4 formylphenyl)-- aminoethyl acetate C H3 0 0 Hz C H2 N- CHO CHQO OzCHrCz All of the=foregoing aldehydes are readily prepared by-reacting the appropriately substituted aniline with di- 1 methyl formamide. Typical processes employing the uselof phosphorus oxychloride are illustrated in the working examples below. The general procedure for the formation of the methine dyesgof this invention follows well-established procedures--and involves the interaction of the two intermediates, that is, the cyanoethyl Patented Oct. 29, 1957 cyanoacetate and n-substituted p-aminobenzaldehyde in the presence of a basic catalyst such as sodium acetate, sodium bicarbonate, sodium carbonate, tertiary amines such as pyridine, piperidine and the like. The process may be conducted in the presence of a non-interfering solvent or diluent such as chloroform, aromatic hydrocarbons such as benzene, toluene, and the like, alcohols such as methanol, ethanol, and the like, etc.

The new methine dyes prepared in accordance with this invention are essentially water-insoluble compounds which may be employed either in aqueous dyebaths or in organic solvent solutions to effect dyeings on the material undergoing coloration. In aqueous dyebaths the dyestuff is present as a dispersion or suspension and such dispersions or suspensions may readily be obtained by several different techniques. Thus the dyestutf may be dissolved in a small amount of solvent such as acetone or alcohol to which an additional small amount of a wetting agent has been added. The resultant solution is then drowned in hot Water resulting in the dyestutf dispersion. An alternative technique involves grinding the dyestufr to a paste in the presence of asuitable dispersing agent such as a sulfonated oil, soap, sodium lignin sulfonate, sodium n-methyl, n-oleyl, n-taurate, formaldehyde condensation products with naphthalene sulfonic acids, known ionics such as polyoxyethylated phenols, alcohols and fatty acids, etc. The grinding or kneading of the dyestuff and dispersing agent may be done in any of the mixers well known for such purposes as, for example, a Werner- Pfleiderer mixer. The resulting paste may be used directly or dried, ground, and safely stored for later use.

Direct dyeings with the methine .dyes of this invention may be conducted at temperatures of about 70 to 90 C., but any suitable temperature may be employed. The textile material to be dyed or colored, e. g. cellulose acetate, is ordinarilyadded to the dye bath at a lower temperature than that at which the main portion of the dyeing is to be conducted. For example, the fabric is introduced at a temperature of about 45 to 55 C., then the temperature is gradually raised to that selected for carrying out the dyeing operation. The temperature at which the dyeing isconducted may be varied depending upon the particular material undergoing coloration. It is understood by those skilled in the art of dyeing that the intensity of dyeing may be varied by varying the proportion of dye to material undergoing coloration. The amount of dye used can be, for example, /2 to 3% by weight of that of the textile material, although lesser or greater amounts of dye can be used.

In the following examples which are offered to illustrate the present invention and are not to be deemed limitative thereof, unless otherwise indicated, parts means parts by weight.

Example 1 Preparation of the dye:

I. Preparation of intermediates: A. 5,5'-phenylimino-bis-ethy1 acetate:

@monnorm 2(GHsCO)zO Q-Monznomom cnsooin CO GHqOHgCN (temperature increased to 37 reflux for 30 minutes,

i in this three-step Calculated for C14H1904N: nitrogen, 5.28. Found: nitrogen, 5.20.

B. p,fl-(4-formylphenyl)-irnino-bis-ethyl acetate:

In a 500 ml., three-necked, round-bottomed flask con taining 100 parts undistilled fl,,6-phenylirnino-bis-ethyl acetate derived as described above and 73 parts of dimethyl formamide, there is added dropwise over a period of 30 minutes at 10-20, 153 parts of phosphorus oxychloride with stirring. After the addition, the reaction mixture is warmed on a steam bath for one hour (90-100) and allowed to stir at room temperature overnight. The viscous reaction mixture is drowned in 400 ml. of ice water. With the temperature being maintained below 20", there is gradually added 370 ml. of 40% sodium hydroxide solution (final mixture pH 4-6). The resulting heavy, pale yellow oil is extracted with several portions of chloroform. The combined extracts are dried, and the solvent removed. The residue is distilled, and the product is collected at 193-5 at 0.08 mm. The yield for the combined steps of acetylation and formylation is 48% of theory.

.Calculated for C15H19O5N: carbon, 61.73; hydrogen, 6.52. Found: carbon, 61.50; hydrogen, 6.67.

II. Condensation to form methine compound:

29 parts of crude 13,5-(4-formylphenyl)imino-bis-ethyl acetate contained in 60 ml. chloroform is combined with 14 parts of cyanoethyl cyanoacetate and 5 drops of piperidine is added as a catalyst. The mixture is heated under after which the chloroform is removed by distillation and replaced with methanol.

. Upon cooling and scratching, crystallization is induced. There is obtained 14.5 parts of a green-yellow solid melting at 90-4". Since crude intermediates have been used synthesis, the overall three-step yield is only 38% of theory.

Example 2 Preparation of the dye:

CN (CHaCHzC OzC:H4)2N-CH=C \COQC2H1UN I. Preparation of intermediates: A. fl,;8-phenylimino-bis-ethyl propionate:

In a suitable vessel are combined 181 parts of ,6,/5"- phenylimino-bis-ethanol and 186 parts of propionic anhydride. After heating on a steam bath for 2 hours the generated acid and excess anhydride are removed and the There is obtained 265.5 g. of a product boiling at 146-8 at 0.1 mm, and having the above structure (91% of theory).

B. B,fi'-(4-formylphenyl)-imino-bis-ethyl propionate:

wmomoommonanwQcno In a suitable vessel are combined 146 parts of 8,5- phenylimino-bis-ethyl propionate and 55 parts of dimethyl formamide. With the temperature maintained at 10-20 C., there is added dropwise during the course of 35 minutes 94 parts of phosphorus oxychloride. The reaction mixture is allowed to stir at room temperature for 1 hour C.) and then warmed on a steam bath for 1 hour (90-100"). After cooling for 1 hour, the reaction mixture is drowned in ice and water and processed as described in Example 1, part B. An aliquot portion is distilled under reduced pressure. There is obtained a heavy amber-colored oil boiling at 20l2 at 0.07 mm. The yield is of theory.

. V .Calcnlatcd for Cl'IH23Q5Nj carbon, 63..5;.-.hydrogen,

7. 17; nitrogen,;, 4.36. Foundz hcarbon ;irhydrogn,

6.9.9.;n trogen, 4.5.5.1

II. Condensation to form methine compound Cyanothethyl. ,u cyano4+di-(fl propionoxyethylyamino cinnamate':

About 32 parts of crude -fl,p';-(4 formylpheny1)-irnino bis-ethyl propionate contained in about 50 m1. of chloroforin is combined with14 ml. of cyanoethylcyanoae'et'ate and drops of piperidine is addedas eatalyst. The"'1'e-' action mixture is heated under reflux for 30 minutes, the chloroform removed by distillation and the residue crystallized' from 200ml. of2-propanol. There is obtained 35. 5 g. of a'green-yellow solid; melting point 89--9l". Since crude starting materialhas been used in this preparation, the yield of 83% represents the yield .for the two.step's-forrnylation and condensation;

Example 3 ,rerera p th .dy

I. Preparation of intermediates:

p, fi"-'(m -tolyl)iminobis cthyl propignate:

(omcmcorcmcmnu-c? HI suitable reaction vessel there are combined .195

In a partsof anhydride. as in Example 2, part product of above structure boiling at 14759 at 0.2 (94.5% yield).

B. p,B'- (3-methy1-4-formy1phenyl)-iminobis;ethy1 proien te wawmcowmcmm-Qom In a suitable reaction vessel are combined 148.5 parts of B,,8'-m-tolylimino bis-ethyl propionate and 44 parts of dimethyl formamide. During 40 minutes there is added dropwis'e' 56 parts of phosphorus oxychloride: The exothermic reaction is maintained at 30 3 i means of 7 After the addition, the mixture is stirred ter'nal cooling. v v

temperature and for '1 houron a steam 1 hour at room bath. After cooling, the vis'cous mass'is' drownedin 500 ml. of an ice-water mixture. There is gradually added 188 ml. of 40% sodium hydroxideto neutralize the acids resulting from the hydrolysis of the phosphorus oxychlorides and their amine complexes. The final mixture has a hydrogen ion concentration of pH 36. Theresulting oily product is extracted with chloroform. The combined extracts are washed and dried. The product is not further purified. e

II. Condensation to form methine compound:

Cyanoethyl 0c cyano 2"- methyl 4 di (p propionoxyethyD-amino cinnamate;

About*32.5 partsof crude aldehyde from Example 3,

Part B (above)' contained in chloroform, 13 parts of cyanoethyl cyanoacetate, and 5 drops of piperidine are heated under reflux for minutes. The chloroform is removed and the residue crystallized from 250 ml, of

2-pjropanol'. -There' is obtained 35.5 parts of a bright, gree'ri' yellow solid melting at 122-4". Based on the two steparqrmy auen and condensation, the yield is 80% of dioxyethyl-m-toluidine and325 parts of propionic The reaction is carriedout' and worked" up A. There is obtained 281' parts of -4 anhyd'ride. A fter warming on a steam bath for two hours,

the-generated ace cjacid .and excess anhydride ,are removed u I, I, nfa steambath fortwo hours (90-100 allowedt 1 v ice and water With the.t'emperature being maintained at 5- 15., tl e is added por-tionwise .220 ml. of,40% sodiuin hydroxidein a" final pH 01:44. .The resulting oil is extracted with lchloroform. The combined extracts are' washed acid free ;and 'dried, the solvent' removed, and the residue distilled underreduced pressure. There is obtained 75g5 partsof product boiling at, 163 at, 0.4mm.

The fcombined yield for the ,two I steps-acetylation and formylation amounts to 64% .Of theory.

Calculated for CraHmOsNi carbon, 66.3; .hydrogem 7.3; nitrogen, 5.95. Foundz carbon, 66.5; hydrogen, 7.23; nitrogen, 5.94.

II. Condensation to form methine compound:

About 11.85 parts of the appropriate pure aldehyde, 6.5 parts of cyanoethyl cyanoacetate, and 5 drops of piperidi ne are combined with 60 ml. of 2-propanol. The mixtureisheat'ed'for several minutes and upon cooling the green-yellow solid product separates. There is phtheory).

Example 5 Preparation of the dye; CHgCHrCQzQHzCH: 0N

. NI. Q,H=.C\

Q h a i v ,GQaQHaQHaQN I. Preparation of intermediate: i p N-ethyl-fl-(4-formylphenyl) aminoethyl propionate:

CHaCH'iCOzCHaCE:

' CHsGH:

About 82.5 parts of N-ethyl-fl-phenylamino ethanol is acylated with 78parts of propionic anhydride as detailed 4. There is obtained 82.5:parts of product; boiling point 166 at 0.4 mm; The two-step yieldfor acylation' and formylation--is 66% of theory.

Calculated for C14H1903N: carbon, 67.3; hydrogen,

7.61; nitrogen, 5.62. Found: carbon, 67.47; hydrogen, 7.41; nitrogen, 5.41.

II. Condensation to form methine compound:

70 About 12.5 parts of pure propionate aldehyde, 6.5 parts 40 ml. of 2-propano1 are combined and heated under reflux for several minutes. Upon cooling the green-yellow product separates. There is obtained 12 parts of prodv uct; melting point 64-8 (66% brawl- 'nder ,i' educed pressure. T 61 the residue, is, added sfof dirnethyltorniamideg To'this well stirred 1 fis"added 'dropwise 93 parts fphos. e. Aftertheadditionthe reaction inix- '01 to 40 andthendrowned in an excess of in Exams-164. "Without isolation and purification of this acylatedmateria'l, it is 'forrnylated 'b y means'o'f dimethyl formamide and phosphorus oxychloride as in Example of cyanoethyl cyanoacetate, 5 drops of 'piperidine,v and.

Example 6 Preparation of the dye: CH|CH2CO1CHrCH1 C N N CH=C\ CHaCfl: CH COaCHzCHaCN About 90 parts of N-ethyl-fi-(m-tolyl)-aminoethyl alcohol and 78 parts of propionic anhydride are combined and caused to react as detailed in Example 4. Without isolation of this acylated material, it isformulated by means of dimethyl formamide and phosphorus oxychloride as in Example 4. No attempt is made to purify this liquid product. The crude aldehyde condenses readily with ethyl cyanoacetate under the usual'conditions to yield a solid methine derivative; melting point 77-8 II. Condensation to form methine compound:

About 26.3 parts of crude acylated aldehyde from I above, 14 parts of cyanoethyl cyanoacetate, drops of .piperidine, and 50 ml. of chloroform are heated under reflux for 30 minutes. The chloroform is removed and the residue crystallized from 500 ml. of 2-propanol. There is'obtained 30.8 parts of a bright green-yellow solid; melting point 78-80. The yield of 81% represents the conversion for three steps,acylation, formylation, and condensation.

'1 Example 7 Preparation of the dye:

cg. /CN

CHQC 01([JHCHI COrOHzCHsCN 'I. The intermediate aldehyde (N-methyD-N-(4-formylphenyl)-aminoisopropy1 acetate, is prepared in the manner disclosed in my copending application Serial No. 372,400, filed August 4, 1953. 1

II. Condensation to the methine dyestuif:

About 11.9 parts of the above described aldehyde, 6.5 parts of cyanoethyl cyanoacetate, 1 part sodium acetate and 50 ml. of 2-propano1 are heated for 30 minutes under reflux. An excellent yield of dyestufi separates upon cooling.

Example 8 Preparation of the dye:

CHICO CHCH,

utes whereby an excellent yield of the dyestutf is ob tained.

COzOHICHgCN Example 9 Preparation of the dye:

CICHICH} CN (uncommon,

COnCHaOHgCN 8 a I. The intermediate aldehyde, Z-N-(fi-chloroethyD-N- (4-formylphenyl)-aminoethylacetate, is prepared in the manner described in No. 372,400.

II. Condensation to the methine dyestuif:

y aforementioned application Serial About 13.5 parts of the above described aldehyde, 6.5"

parts cyanoethyl cyanoacetate, 1 part sodium bicarbonate and parts of 2-propanol are heated under reflux for about 25 minutes; upon cooling an excellent yield of methine compound is obtained.

Example B 0.2 g. of a dye composition comprising dyestufi of Example 3, 37% sodium lignin sulfonate and 8% sodium sulfate is dispersed in 250 ml. of water.

A. 10 g. piece of cellulose acetate cloth is immersed in the above described dyebath at a temperature of F., the temperature is then raised to F. and held there for 1 hour, after which the cloth is removed, rinsed and dried. The resultant dyed cloth exhibits outstanding levelness of dyeing and has excellent lightand washfastnes's.

Example C I A composition is prepared employing 55% methine dye similar to that of Example 3 in that the aldehyde moiety is the same but the active methylene compound employed is methyl cyanoacetate instead of cyanoethyl cyanoacetate, 37% sodium lignin sulfonate and 8% sodium sulfate. 0.2 g. of this composition is dispersed in water and a 10 g. piece of cellulose acetate cloth is dyed in a manner identical to that described in Example B. The resultant dyed cloth has about one-half the tinctorial strength of the dyed cloth of Example B.

Example D The dyeing procedure of Example B is repeated utilizing as the dye composition the following:

50% dyestufi. of Example 4 40% sodium N-methyl, N-oleolyl taurate 10% sodium sulfate 7 Example E A composition similar to that of Example D is prepared except that the dye is that of Example C. Example D is then repeated in its procedure for preparing the dyebath and dyeing the acetate cloth. As described in Example D, the tinctorial strength of the dyed cloth is greatly inferior to that of Example D.

Example F Example D is repeated except that the dyestuif em ployed is the one of Example 5 instead of Example 4.- Again the results are excellent and the dyed product has, again, about 50% greater depth of color than the dyed product of Example E.

- Example, G

suchmodifications and variations are to be included with 9 10 in the spirit and purview of this application and the scope 3. oflthtle eppended claims. (uncommon, (3N

c arm: 1. Compounds of the following general formula: OH=C R ON CEO 1 COzOHsCHzCN 4 /N- CH=G\ R,co,cricrr, 001011201110 E' NCH=C R3 10 l on on UN wherein R1 is a radical selected from the group consisting of aralkyl, alkyl radicals of 1 to 6 carbon atoms and hydroxy chloro, cyano, and alkoxy substituted derivacmcmcmcmcfl, ON tives thereof, and the groupin'g CH=O/ R,oo, :11om 15 omen, coicnlcaiorz RI H wherein R2 is a lower alkyl radical, R3 is selected from the group consisting of hydrogen, lower alkyl, and acylon, or: oxymethyl and X is selected from the group consisting CH=C/ of hydrogen and lower alkyl. g

0111000110 1 COIGHICHICN ON (cmomc ommcnnm- 0H=0 References Cited in the file of this patent C0:0: 4 N UNITED STATES PATENTS 2,374,880 Mueller May 1, 1945 2,583,614 Taylor et a1. Jan. 29, 1952 2,649,471 Williams et a1. Aug. 18, 1953 2,766,233 Kartinos et a1. Oct. 9, 1956 

1. COMPOUND OF THE FOLLOWING GENERAL FORMULA: 